Field
The present disclosure relates to respiratory therapy systems. In particular, the disclosure relates to interface assemblies for use in respiratory therapy.
Description of Related Art
The treatment of respiratory ailments or conditions with therapies such as non-invasive ventilation (NIV), Bi-level or continuous positive airway pressure (CPAP) therapy involves the delivery of pressurized air to the airways of a human via a conduit and an interface (e.g., a mask). Some types of interfaces create at least a substantial “seal” on or around the nose and/or the mouth of the user.
The result of creating this “seal” is that the combination of the enclosure area of the interface and its internal pressure creates a resulting force (a “blow off” force) that attempts to push the mask off the face. To restrain this force it is normal to use a headgear arrangement having one or more straps that pass around the back of the head.
The strap(s) require some form of adjustment to account for variation in head size, this adjustment mechanism is typically provided via an adjustment loop between the mask body and the head gear. The adjustment loop can have a hook-and-loop or similar fastener that permits an end of the strap to be passed through a mounting location on the mask or through a clip that attaches to the mask and then attached to another section of the strap. Such an arrangement permits adjustment of the headgear by positioning the end of the strap at a desired location on the other section of the strap to vary a size of the adjustment loop.
These types of mechanism are one solution to providing an adjustment mechanism for the headgear and, thus, the interface assembly. Such systems also require a reasonable level of user interaction and, as a result, is prone to misuse or mis-adjustment (e.g., over-tightening). As a practical matter, micro-adjustment of such systems is difficult and time-consuming to accomplish. The creation of practical and not so practical solutions to this has been the subject of considerable development effort from a number of organisations, which has resulted in numerous patents.